Drink driving has been prohibited in some form for more than a century, but the law did not develop on a single date. Early legislation focused on whether someone was visibly drunk or unable to control a vehicle. The measurable legal alcohol limit and roadside breathalyser system familiar to drivers today arrived much later.

So, when did drink driving become illegal in the UK? The first law covering drunkenness in charge of transport appeared in 1872, while the first specific offence involving a mechanically propelled vehicle was introduced in 1925. However, the Road Safety Act 1967 created the first legal drink drive limit and introduced breath testing.

This history of drink driving, prepared by the drink driving offence solicitors at JMW, explains how the law moved from subjective assessments of a driver’s condition to scientific alcohol analysis and evidential breath testing. 

When Was Drink Driving First Made Illegal?

The answer depends on what is meant by drink driving. The Licensing Act 1872 made it an offence for a person to be found drunk while in charge of a carriage, horse, cattle or steam engine on a highway or in another public place. This law predated the widespread use of motor vehicles, but it established the principle that intoxication while controlling transport could amount to a criminal offence.

The first legislation specifically addressing motor vehicles was section 40 of the Criminal Justice Act 1925. It made it an offence to be drunk while in charge of a mechanically propelled vehicle on a highway or in another public place. A person convicted under the original Act could face imprisonment for up to four months, a fine or both.

Drink driving was therefore illegal before the introduction of the modern alcohol limit. However, the early law did not set a measurable blood alcohol concentration. The authorities instead had to establish that the motorist was drunk or unable to exercise proper control.

What Laws Applied Before Cars Became Common?

The Licensing Act 1872 is sometimes described as Britain’s first drink-driving law. Strictly speaking, it was a wider public-order law rather than legislation designed for the British motor industry.

Its wording referred to carriages, horses, cattle and steam engines. It did not refer to the modern motor car because privately owned cars were not yet a common feature of British roads. Nevertheless, the Licensing Act established an early connection between drinking alcohol and the unsafe control of transport.

As cars became more widely available, Parliament needed legislation that dealt specifically with motorists. The Criminal Justice Act 1925 filled that gap by creating an offence involving a mechanically propelled vehicle.

The 1872 and 1925 laws relied heavily on observations of the person’s behaviour. There was no roadside breathalyser and no scientific legal alcohol limit. Police officers and witnesses instead had to provide evidence that the person was drunk.

How Did the Road Traffic Act 1930 Change the Law?

The Road Traffic Act 1930 developed the offence further. It addressed anyone driving, attempting to drive or being in charge of a motor vehicle while under the influence of drink or drugs to such an extent that they were incapable of having proper control of the vehicle.

This broadened the focus beyond simply being “drunk”. The central question became whether the influence of alcohol affected the person’s ability to drive properly.

However, prosecutions still depended on subjective tests. Evidence might include erratic driving, slurred speech, unsteadiness, the smell of alcohol or the driver’s conduct when stopped. There was no objective alcohol limit against which a sample could be measured.

The same broad approach continued under later road traffic legislation. Although drink driving was already a criminal offence, proving alcohol impairment could be more difficult where a person did not show obvious signs of intoxication.

What Changed in 1967?

The Road Safety Act 1967 marked the beginning of the modern drink-driving system.

The Act introduced the first statutory legal drink drive limit in Great Britain. It set the prescribed limit at 80 milligrammes of alcohol per 100 millilitres of blood. It also created the legal framework for roadside breath testing and the use of blood or urine specimens for laboratory testing.

This was a major change because the prosecution no longer always needed to prove that the person appeared incapable of driving safely. A motorist could commit a drink driving offence by driving or being in charge with a blood alcohol concentration above the prescribed limit.

The roadside breathalyser provided an initial indication of whether a person might be above the alcohol limit. Where the test indicated excess alcohol, the police could require further specimens for analysis.

This means that 1967 is often described as the year drink driving became illegal. More accurately, it was the year the UK introduced the first measurable legal alcohol limit and modern breath-testing regime.

The drink drive limit remained 80mg of alcohol per 100ml of blood in 1972. The Road Traffic Act 1972 consolidated the existing offences relating to driving while unfit, driving above the prescribed alcohol limit, breath tests and laboratory specimens.

Why Was the Breathalyser So Important?

The introduction of the breathalyser gave the police a faster and more objective way to identify suspected drink drivers. Research showed that drivers with a blood alcohol level of between 50mg and 80mg per 100ml of blood were around six times more likely to be involved in a fatal collision. Following the introduction of breath testing, the proportion of road accidents linked to alcohol reportedly fell from 25 per cent to 15 per cent.

Before the roadside breathalyser, officers largely relied on physical signs and driving behaviour, such as slurred speech, unsteadiness, the smell of alcohol or erratic driving. Although this evidence could be important, it did not provide a precise alcohol reading. Breath testing introduced a more reliable scientific measure that could support a decision to arrest a motorist and carry out further analysis.

A police officer cannot generally conduct random breath testing without a lawful basis under the Road Traffic Act. An officer may require a preliminary breath test where there is reasonable cause to suspect that a person has alcohol in their body, has committed a moving traffic offence or has been involved in a road traffic accident.

Failing to provide a required specimen without a reasonable excuse is itself a criminal offence. Whether a person had a reasonable excuse will depend on the circumstances and may require medical or other supporting evidence.

How Has Drink-Driving Law Developed Since 1967?

Further reforms made breath testing more central to drink-driving investigations.

The Transport Act 1981 provided for evidential breath testing at a police station. The system came into operation in Great Britain on 6 May 1983. Before this change, a roadside breathalyser generally acted as a screening device and the final evidence usually came from a blood or urine specimen. Approved evidential machines allowed the police to obtain the formal reading directly from breath specimens.

The Road Traffic Act 1988 now contains the main drink-driving offences in England, Wales and Scotland. These include:

• Driving or attempting to drive while unfit through drink or drugs.
• Being in charge of a motor vehicle while unfit.
• Driving or being in charge with alcohol above the prescribed limit.
• Failing to provide a required specimen without reasonable excuse.

The law therefore continues to distinguish between exceeding the legal limit and being unfit through the influence of alcohol. A driver may be prosecuted for being unfit even where the evidence does not establish a reading above the prescribed alcohol limit.

The High Risk Offender Scheme was also introduced in 1983. Certain convicted drink drivers must satisfy the Driver and Vehicle Licensing Agency that they are medically fit before receiving a new driving licence. Current high risk offender categories include some repeat offenders, motorists with particularly high alcohol readings and people convicted of refusing to provide a specimen.

Is the Drink-Drive Limit the Same Across the UK?

Scotland has a lower legal limit than England, Wales and Northern Ireland.

In England, Wales and Northern Ireland, the legal alcohol limits are:

• 35 microgrammes of alcohol per 100 millilitres of breath.
• 80 milligrammes of alcohol per 100 millilitres of blood.
• 107 milligrammes of alcohol per 100 millilitres of urine.

Scotland reduced its drink drive limit on 5 December 2014. Its limits are:

• 22 microgrammes of alcohol per 100 millilitres of breath.
• 50 milligrammes of alcohol per 100 millilitres of blood.
• 67 milligrammes of alcohol per 100 millilitres of urine.

There is no reliable answer to whether two pints will put someone over the drink-drive limit. Alcohol affects people differently according to factors such as body size, sex, metabolism, food consumption, drink strength and the time between drinking and driving. The only safe approach is not to drive after drinking alcohol.

There is also no general “two-hour rule” that makes driving lawful after two hours. Alcohol can remain in the body for considerably longer, including the following morning. Coffee, sleep, food and cold showers do not remove alcohol from the bloodstream; only time reduces the concentration.

Can You Be Convicted Even If You Are Below the Legal Limit?

A person can commit an offence if alcohol has made them unfit to drive, even where their reading is below the legal drink drive limit.

Under the Road Traffic Act 1988, a person is unfit where their ability to drive properly is impaired through drink or drugs. Evidence may include the standard of driving, physical symptoms, the person’s behaviour and the results of impairment assessments.

The prescribed limit is therefore not a target or an indication that drinking before driving is safe. Even a relatively small amount of alcohol can affect reaction times, judgement, concentration and coordination.

What Are the Current Penalties for Drink Driving?

A person convicted of driving or attempting to drive while above the legal limit or unfit through drink may receive penalties such as:

• Up to six months’ imprisonment.
• An unlimited fine.
• A driving disqualification lasting at least one year.
• A minimum three-year ban if convicted of another relevant drink-driving offence within 10 years.

Refusing to provide a specimen of breath, blood or urine without reasonable excuse can also lead to up to six months’ imprisonment, an unlimited fine and a driving ban of at least one year.

Causing death by careless driving while under the influence of drink can result in life imprisonment. The maximum sentence increased from 14 years to life imprisonment for offences committed on or after 28 June 2022. The court may also impose an unlimited fine, disqualify the person from driving for at least five years and require them to pass an extended driving test before their licence is returned.

Some motorists disqualified for 12 months or more may be offered an approved drink-drive rehabilitation course. Completing the course can reduce the disqualification period, but only where the court has offered this option.

Take a look at our drink driving penalty calculator to understand what you may be liable for.

What Should You Do If You Are Accused of Drink Driving?

Drink-driving allegations can involve questions about the initial stop, roadside testing, police station procedure, specimen requirements and the accuracy or admissibility of the evidence.

Our motoring offences solicitors examine:

• Whether the police had lawful grounds to require a breath test.
• Whether officers followed the correct statutory procedure.
• Whether the evidential breath-testing equipment was used correctly.
• Whether a medical condition affected the provision of a specimen.
• Whether a reasonable excuse applies to an alleged failure to provide.
• Whether evidence supports an allegation that the person was driving or in charge.
• Whether special reasons may affect disqualification.

Seeking advice promptly gives us the opportunity to review the evidence, explain the available options and prepare the case before the first court hearing.